Pentanone
Pentanone is a ketone with the molecular formula C5H10O. It exists as three structural isomers: 2-pentanone (methyl propyl ketone), 3-pentanone (diethyl ketone), and 2-methyl-3-butanone (methyl isopropyl ketone). Each isomer possesses a carbonyl (C=O) group, the defining characteristic of ketones. The position of this carbonyl group differentiates the isomers.
2-Pentanone has the carbonyl group on the second carbon atom of the five-carbon chain, while 3-pentanone has it on the third. 2-Methyl-3-butanone, also a pentanone isomer, has a branched four-carbon chain with a methyl group attached and the carbonyl group on the third carbon.
Pentanones are colorless liquids with characteristic acetone-like odors. They are used as solvents, particularly in the paint, varnish, and adhesive industries. They can also serve as intermediates in the synthesis of other organic compounds. Pentanones are flammable and should be handled with caution.
The different isomers of pentanone possess varying physical and chemical properties. For example, their boiling points and solubilities differ slightly. These differences are attributable to the varying positions of the carbonyl group and the presence or absence of branching within the molecule.